高压开关设备弹簧断裂分析

Analysis of Spring Rupture in High-Voltage Switchgear

【目的】在对高压开关设备样机进行寿命模拟试验时弹簧发生断裂,需要分析弹簧断裂失效的原因。【方法】利用化学成分分析、硬度测试、宏观检测与SEM分析、金相检验、断口分析等失效分析法对弹簧断裂原因进行分析。【结果】弹簧的断裂为疲劳断裂,断口微观形貌存在较为明显的疲劳辉纹。【结论】弹簧的断裂失效是其折弯处存在表面损伤缺陷,降低弹簧的疲劳强度。当设备进行操作试验时,该损伤处易萌生裂纹,最终导致弹簧发生疲劳扩展和断裂。

[Purposes]During the life simulation test of the high-voltage switchgear prototype,the spring broke.Therefore,this study aims to identify the cause of spring fracture failure.[Methods]Failure analy-sis methods such as chemical composition analysis,hardness testing,macroscopic examination and SEM analysis,metallographic examination,and fracture analysis were used to study the cause of its fracture.[Findings]The fracture of the spring is fatigue fracture,and there are obvious fatigue striations on the mi-crostructure of the fracture surface.[Conclusions]The fracture failure of the spring is mainly due to sur-face damage defects at its bending point,which reduces the fatigue strength of the spring.When the equipment is operated and tested,cracks are prone to initiate at this damage point,ultimately leading to fatigue propagation and fracture of the spring.